He has warned the US President to not be 'very stupid'.

Explorer Sir Ranulph Fiennes - one of a handful of people to witness the devastating effects of climate change firsthand - has warned Donald Trump about his attitude to the environment.

Fiennes, whom the Guinness Book of Records has named “the world’s greatest living explorer”, said he feared the US president “wants to ignore the bad things” happening when it comes to climate change.

The 73-year-old, who was the first person ever to have both summited Everest and crossed the polar ice caps, was speaking to HuffPost UK between attempts to climb the tallest mountains on the world’s seven continents.

He said leaders like Trump and Theresa May had to do everything possible to “get climate change under control”.

Before he was elected president, Trump claimed global warming was created “by and for the Chinese in order to make US manufacturing non-competitive”.

When HuffPost UK asked Fiennes about the evidence he has seen of climate change, he recalled two expeditions to the Arctic Ocean, two decades apart.

He said the landscape in the Arctic has visibly altered as a result of climate change, more noticeably so than in Antarctica.

PA Archive/PA Images
Sir Ranulph Fiennes (l) and Charles Burton (r) trekking across the Arctic wastes on their way to the North Pole.

He told HuffPost UK: “The Arctic Ocean... being an ocean with a little bit of ice floating around on it, that’s very different [to Antarctica].”

“In the 1970s we in the Arctic Ocean, the North Pole expeditions, (were) breaking world records using sledges... [that were designed] so that they were sort of waterproof in case we met canals of water in between the ice.”

But the sledges designed for the expedition in the 1990s had to be built to function as canoes to cross large areas of open water, because of how much ice had melted there.

“It was a huge difference and now it’s an even greater difference,” Fiennes said.

The World Wildlife Foundation (WWF) has said the Arctic is warming at a rate of almost twice the global average.

Although the clock is ticking, with campaigners stressing the need for urgent action to slow down climate change, not everybody sees it as a priority.

Trump’s first 100 days as president was slammed as being “catastrophic” for the environment.

There are growing fears that Trump could back out of the Paris Agreement on climate change.

While a US exit will not signal the end of the deal, it would significantly undermine its credibility and impact the agreement’s target of preventing temperatures from rising more than 2°C by the end of the century.

“If one nation, especially the biggest nation... if they do not recognise a problem, then we will have trouble dealing with the causes”, General Denis Mercier, NATO’s supreme allied commander for transformation, told Reuters.

Carlos Barria / Reuters
Campaigners fear Donald Trump could back out of the Paris Agreement.

When asked whether he was concerned about Trump’s attitude to climate change and the environment, Fiennes said: “I am concerned about anybody who wants to ignore the bad things which are happening in an atmosphere which could be changed by the sensible self preserving, i.e. humans, who want to preserve their existence for longer in the face of this threat.

“It would be very stupid to put temporary business interests for your own generation ahead of the survival chances of your next generations.

“So whether you’re Donald Trump or Mrs May, then you should do the best you possibly can to use science to help get climatic change under control.”

Asked whether he thinks enough is being done to slow down climate change, Fiennes said: “Whenever you have done something against climate change then you should immediately start on the next thing. Never say it’s enough.”